Sheet rolling process and apparatus



Dec. 1, 1936. G. P. HANSEN SHEET ROLLING PROCESS AND APPARATUS Filed June 22, 1952 2 Sheets-Sheet l INVENTOR ATTORNEYS Dec. 1, 1936.

. SHEET ROLLING PROCESS AND APPARATUS G. P. HANSEN 2,062,309 I I Filed June 22, 1952 2 Sheets-Sheet 2 Patented Dec. 1', 1936 UNITED STATES PATE NT OFFICE SHEET ROLLING PROCESS AND APPARATUS tion of Ohio Application June 22, 1932, Serial No. 618,603

4 Claims. (01. 29-18) My invention relates to the production of rolled sheet metal by a continuous process whereby the sheet stock is successively reduced by passes through a sequence of nonrevers'ibly driven roll stands, each associated with suitable tables and preferably mechanically operated roll adjusting screws, all automatically controlled, to subject the sheet stock, whether in the form of sheet or tin plate bars, packs, rough plates, thin bars, or other suitable stock, to the desised number of back and forth or shuttle passes in any or all stands, until finished to the desired sheet gauge, with or without initial and/or intermediate heating of the stock and with or without the customary matching and/or doubling according to the character of the stock being reduced and the end product desired.

Being concerned with the production of sheet metal, which term as I use it is inclusive of thin wide plates, sheets, and tin plate stock, I have observed that certain very marked economies in manufacture have resulted from the change of the hand operated hot rolling operation to a continuous process in which the stock passes continuously and without reversal of direction of.movement through a series of roll stands by which it is successively reduced to proper gauge for matching and, forming into packs and after segregation of the packs for comparative uniformity and re-' heating, the reduction process is completed in a different continuous finishing mill or mills.

I have conceived, however, that further economies in sheet rolling cost can be obtained, if a continuous treatment can be evolved which is so rapid, that in hot rolling there will be no increase in the cost of the heating factor; so flexible, that it can readily be adjusted to work any selected sheet stock such assheet bars, plates or packs into any variety of finished or semi-finished sheets (limited of course by the reducing capacity of the mill) required for the trade or for further processing as in a tin plate mill; so simple as to its control factors, that comparative uniformity of the predetermined gauge and size of the rolled stock can be relied on; and so inexpensive in respect of outlay for plant, that a marked reduction will result in the overhead factor covering interest on invest 'ment, obsolescence, and depreciation, as wellas in vious that the existing continuous mills can be economically availed of only for rolling large tonnages of a given sheet product because of the cost and time loss for effecting roll changes and adjustments.

The very marked difference between my contin uous mill equipment and that heretofore employed for continuous sheet rolling is exemplified in two important respects, namely, plant cost and simplicity of roll adjustment. As to the former, my process can be installed at a cost for a complete continuous plant amounting to only a fraction of that of the necessarily greater capacity continuous sheet mills now in use; and as to the latter, by the-employment of automatically controlled mechanical screw downs the one mill operator required can easily and quickly set them to predetermine, accurately and uniformly, the roll clearances for each of the required passes and can readily vary the number of passes for the stock. This facility for providing mechanically a, substantially invariable predetermined pass clearance for the selected number of passes has led to a new conception asto the control of the finished product in a hot rolling process as to surface dimensions and/or gauge.

Heretofore, in-hot rolling practice, it has been attempted to utilize the dimensions of the stock, such as its length or its thickness, to control the number of roll passes. This has occurred in the control of the tables of a single two or three high non-reversibly driven mill with hand control of the screw down adjustments. Obviously, such practice lacks that accuracy and definiteness reqk bility as to predetermined roll clearances after any given setting throughout the continuous mill, a variable factor that is of the simplest possible character must be introduced to enable the control of the surface dimensions and/or gauge of the sheets to be at all times maintained. To this end I propose to provide the continuous furnace, in which the stock is heated, with an automatic heat regulation capable of being set by the mill operator to raise, or lower the temperature of the stock delivered to the mill, thereby to modify its reduction through fixed roll clearances. This control is thus based upon the operator, when observing any excess or deficiency in measurements,

not calling for roll clearance adjustments,.to correct same by raising or lowering the requisite temperature for the furnace, it being understood that, notwithstanding fixed roll clearances, the v spring in the rolls and their mountings, and also the varying sensitivity to treatment of different batches of stock even though of like analysis, due to some characteristic thereof at the temperature selected for the continuous furnace, will produce varying results in like dimensional stock at the same temperature. While this fact is of course well known, it has never been takenadvantage of in connection with the operation of a mill having predetermined mechanically attained roll clearance adjustments for the shuttle passage of the stock.

My invention'further, in one of its phases, contemplates the provision of a combination of mills, one to receive the stock and by a mechanically accomplished shuttle passing of the stock through the rolls, to rough it and deliver the roughed sheets quickly to be pack-matched and finished by one or more like shuttle passes back and forth through a second millin the series acting continuously to finish the reduction of the stock. The mills selected should suit the work, a three high hot process roughing mill being suitable for producing the break downs which then, according to the gauge desired, will be finished on one or more mills, the stock passing in either case continuously and without material loss of time and without any manual handling from roughing to finishing mills. There may be oneior more roughing stands and one or more finishing stands with or without an interposed reheating treatment.

As applied to cold rolling, my invention contemplates roughing the preheated stock in any hot process mill desired and continuously finish,- ing it in one or more stands of cold rolls, preferably of the four high or of the six roll cluster type, with either solid or hollow rolls.

Obviously, great flexibility presents itself in the utilization of my continuous process as applied to a hot rolling shuttle movement of the preheated stock to rough it and produce its maximum reduction economically in a single stand, followed with or withoutpack-matching and then finishing the roughed stock on one stand, or a carried into efiect by means of the apparatus such as is illustrated in a formal manner in the.

accompany n d awings, in which Fig. 1 presents, in vertical longitudinal cross section,ia threehigh mill having automatic feeding and catching tables to be associated with an automatic screw down such as'shown in Fig. 4, all

. controlled by the passage of the stock and designed to produce a selected number of shuttle having automatic temperature controls subject, to manual regulation by the mill operator;

Fig. 3 is a view similar to Fig. 2 in which-the heated' blanks are roughed by a sequence 'of passes on a three high mill to produce break downs which, after matching and reheating, are finished by a sequence of passes, having predtermined roll clearances, in a three high finishing mill;

Fig. 4 is a view of a three high mill for roughing sheets with an automatic screw mechanism controlled by the stock which is pack-matched and then finished by a sequence of cold rolling passes through four high mills;

Fig. 5 is a detail' view of the automatically tripped limit switches which control the step by step setting and the resetting of the rolls to provide the predetermined roll pass clearances in the mill it controls;

Fig. 6 is a diagrammatic view of a three high shuttle action mill for roughing in series with a four high shuttle action cold process mill having rying out my process.

.Similar references. refer to similar parts.

throughout the drawings.

In the mechanism illustrated in Fig. 1, I have shown a heating furnace ID from which the sheet blanks are automatically delivered at timed intervals by means of a conveyor l I to the conveyor chains on the feed table l2 for a three-high nonreversibly driven mill comprising the lower r011 l3, the intermediate small roll I4, and the large upper roll IS. The large rolls may have double the diameter of the small roll. These rolls are all mounted foradjustment in a roll stand I6 (see Fig. 4) by meansof head screws I! which are automatically actuated by the motor driven mechanism l8 which through limit switch mechanism I!) (Fig. 5)' will under control of the stock produce automatically a sequence of predetermined pass clearances for the stock as it moves between the rolls.

This feed table has associated therewith side matching elements 20 and a stock actuated trip Him a flag switch mechanism 22. A counterweighted stop means 23 is provided for arresting the blanks adjacent to the rolls. .A power cylinder 2!, under automatic control, will actuate a ram 25 which engages the stock and after first matching it endwise against the stopmeans 23, will then thrust it past said stop means into the initial roll pass. On the catcher side of the mill a mechanical catcher mechanism adapted to be tilted in a vertical plane by any suitable mechanism, not shown," receives sheet stock from one a pass and returns it to'the other pass. The catcher mechanism as illustrated comprises coacting conveyor chains, reversibly driven, which act to catch the stockfrom the lower pass and to return it to the upper mill pass any desired number of times before discharging it rearwardly onto a second feed table Ila, similar to l2 and its equipment as already described.

Stock entering between the catcher chains will actuate a trip2l, at theintake end of the catcher which controls a flag switch 28 by means of which the vertical tilting movements of the catcher, as well as the manipulation of the screw down mechanism, are automatically controlled responsive to the passage of the stock.

The stock returning through the upper pass between the rolls l4 and I5 will move over a guide 29 to pinch rolls 30 and 3| which are driven by the upper feed table conveyor 32 which runs in a direction to deliver the sheet'stock between the conveyor and pinch roll 3| over a guide 33 back to the lower pass, the guide causing the stock to clear the stop means 23. Each time the flag switch 28 energizes the screw down mechanism, the latter advances the head screws a predetermined distance to set the next roll pass clearance and to trip a limit switch 34 by a trip arm 35 until finally the reversing switch 36 is tripped and the mechanism reset to initial position for a new rolling cycle. All the mechanism so far described is fully detailed in a companion application assigned to the Gulf States Steel Company, Serial No. 609,064, which has matured into Patent No. 2,010,715, and a detail description of such structure is not therefore repeated in this process case. The treatment to which the sheet blanks are subjected in the apparatus shown may be briefly described as follows.

The blanks in the form of roughed shear plates, are heated to a predetermined automatically controlled temperature in the furnace ill and delivered at predetermined intervals to the feed table i2. There. at the moment that the rolls are accurately reset for the commencement of a rolling cycle, the ram 25 is actuated, the matched sheets, if a stack or pair is being handled, are delivered into the lower roll pass and. discharged therefrom into the catcher 26.

When the sheet releases the trip 21 on the catcher, the latter rocks upwardly causing the flag switch 28 to reverse the direction of catcher belts and to cause the screw down to be advanced a predetermined extent to set the rolls for the second pass in advance of the sheets reaching the upper pass. charged from the catcher they again actuate and release the trip 2! setting, with a suitable time delay means interposed, the rolls for the third pass. Sheet stock after the second pass is delivered' to the upper table 32 and returned to the lower roll pass where the cycle can be again repeated for any number of times desired, it being understood that the automatic control of the screw down mechanism and of the catcher will permit a variable number of passes to be very rapidly executed.

The stock after completing the passes on the three-high roughing mill 38 is delivered by the catcher 26 to the feed table l2a, similar to l2, of the finishing mill 99 of the series, this delivery being accomplished directly and without reheating, according to the disclosure in Fig. 2. There the sheets, following the same cycle of control and forth through the finishing mill 39, the rolls It is contemplated that the operator in charge of the continuous rolling mechanism which I have described will .by means of a regulator indicated at 31 on the heating furnace l vary the automatically maintained temperature of that furnace so as to raise or lower it in order that thereby it may care for any minor irregularities in the dimensions of the finished stock which do not call for a readjustment of the automatic program control for the mill screw down.

In Fig. 3 I have illustrated a modification of the process in which a three-high roughing mill 38 comprising rolls l3, l4 and I5, is provided and associated with an automatic feed table l2 and catcher table 26, such as have been already de- As the sheets are dis-' ing process as may be best suited for the scribed. By this means the sheet blanks can be subjected to one or more roughing passes until brought to proper gauge for pack-matching on the table 40. The matched pack is then delivered to a reheating furnace 4| wherein its temperature is raised to the requisite degree to enable the desired number of passes to be carried out on the three-high finishing mill 39, such as has already been described.

My invention as .illustrated in Fig. 4 contemplates any desired number of shuttle passes through a hot process roughing mill 38 and when reduced thereby to the desired gauge the stock will be packed-matched on the feed table 42 for a four-high cold rolling process mill 43 comprising small working driven rolls 4 4 and 45 and large backing up rolls 46 and 41 all mounted normally in any suitable housing such as IE, or using a six-roll cluster type mill, not shown.

It is contemplated that the stock will pass from the mill 43 over table 49 to one or more cold process mills 50 in a continuous non-reversing movement. 4

As illustrated in Fig. 6, the stock, after being reduced to break downs by shuttle passes in the hot process roughing mill 38, will be delivered by its catcher table 26 to the feed table l2a for shuttle passes through a cold process mill 43 having a catcher 26a to return the stock between its rolls 44 and 46 with the pass clearance either unchanged from the preceding pass or enlarged or slightly reduced as rolling conditions may indicate, such changes being automatically provided for by the setting of the automatic screw down control with which each of these mills will be equipped.

- gram control automatically effected for the roll clearance desired to accomplish the reduction contemplated ingeach pass of the series, it will be seen that my process is a continuous one capable of being carried out with as few as two roll stands withor without intermediate heating to reduce a variety of sheet blanks into a variety of finished sheet forms widely variant as to gauge and surface dimensions and with the advantages pertaining to either the hot or cold rolling finishsheets desired.

Heretofore it has not been considered practical to shuttle pass the sheet stock back and forth through a four high mill for any material reduction on the return pass, but the stock under prop er roll adjustment control can obviously be returned by a mechanical catcher table to the feed table side of such a four high mill and again given further reducing passes in the same direction as the first pass, wherever by reason of expense it is not feasible to use for each finishingpass a separate mill of the four high type, or other type with the stock engaging rolls properly backed up.

- Many mills now exist for the production of standard sheet bar, some furnishing the bar for sale to finishing sheet and tin mills, and others being operated in plants in conjunction with these finishing mills. The finishing mill plants have been equipped with a number of two-high hand operated mills such having heretofore been regarded as essentialfor the reduction of the sheet bars to gauge for matching. After sheet bars have been thus roughed in these two-high mills, the practice has been to form them into matched and doubled packs and after reheating they are finished in separate finishing mills which have heretofore been of the hand operated type. These sheet bar mills are now confronted with the necessity of scrapping their equipment because it has become economically impractical to attempt to finish sheet bars on hand mills in view of the improvements in operation and cost reduction that have been made effective through continuous rolling processes which, however, have not heretofore been adapted to work sheet bars, but have been designed and have operated with other initial stock.

A further object of my invention is to enable such mills, finding themselves in this position, to obtain the full value of their sheet bar equipment and the finishing mills to finish it into marketable sheet form by a continuous process that will be economically competitive with other continuous processes and which can be installed and adapted to finish roughed plates without requiring the provision of an expensive plate or strip mill.

My invention also contemplates that the roughed sheets shall be finished without reheating in one or more mills operating on the cold rolling principle. This method of finishing is of particular importance where it is desired to obtain thin or light gauge sheets for various uses and for conversion into tin plates. It is contemplated that the stock delivered to these cold process mills will be in pairs or packs to which the requisite number of passes either of the shuttle type back and forth through a four-high cold rolling mill or by passes without reversal through a sequence of four-high cold mills, the four-high mill being the equivalent of any with small working rolls having large backing up rolls, the small working rolls being preferably the driven rolls,

It is contemplated that the reduction given to the sheets in these cold rolling passes will be sufficient to bring them to a gauge as light or lighter than that required for doubling, it being an added advantage, in so far as tin plate manufacture is concerned, that these sheets shall be reduced to as light a gauge as possible by my proposed mechanical rolling process, as thereby I reduce the manual rolling of the stock for finishing by hand rolling in the tin plate process. This gives the tin plate-manufacturer a partial participation in the advantages, as to cost reduction, derived from ished in three to five finishing passes to say 20 gauge.

In the graph illustrated in Figures 7, 8 and 9,

I have indicated the continuous travel of sheet stock through various reductions effected in accordance with my process.

Fig. 7 illustrates the movement of stock through two roughing passes accomplished in a sequence of roll stands, which may be two or three-high mills, to a three-high finishing mill where it is given three shuttle passes. The dotted .lines indicate the optional employment of five shuttle passes for the stock in the finishing mill.

sequence of two rollstands, either adapted for cold or hot rolling processes. It will be understood that the graphs are exemplary merely and that the number of shuttle passes for roughing or finishing can be increased or decreased according to the character of the stock being worked, its size and temperature, and the gauge of the finished product desired.

While I have shown my invention in several forms, it will be obvious to those skilled in the art that it is not so limited, but is susceptible of various other changes and modifications, without departing from the spirit thereof, and I desire, therefore, that only such limitations shall be placed thereupon as are imposed by the prior art or as are specifically set forth in the appended claims.

What I claim is:

1. A method of rolling metal to finished gauge directly from heated sheet bars and like sheet blanks not lighter than rough plate, and without reheating, which comprises heating said sheet blanks and substantially reducing them by repeated passage through a single roughing mill following a predetermined screw-down program fixed for all blanks of a given batch or order, then deliveringthe reduced pieces to a finishing mill and finishing them, all of the operations of the process at least subsequent to the heating step, being carried on in rapid succession and automatically, including the delivery to the roughing mill, the handling of the pieces in the repeated passes through said mill, the following of the predetermined reduction program for said mill, and the delivery of said pieces to the finishing mill, all of said operations being carried on so rapidly as to render reheating unnecessary, and in connection with said predetermined reduction program controlling the dimensions of the finished sheets by controlling the initial temperature to which the blanks are heated.

2. A method of continuously rolling metal to finished sheet gauge directly from heated sheet bars and like sheet blanks not lighter than rough plate, and without reheating, which comprises heating said sheet blanks and substantially reducing them by repeated passes through a single roughing mill following a predetermined screwdown program, then delivering the reduced pieces to a finishing mill and finishing them, all. of the operations of the process at least subsequent to the heating step being carried on in rapid succession and automatically, including delivery to the roughing mill, the handling of the pieces in the repeated passes through said mill, the following of the predetermined reduction program for said mill, and the delivery of the pieces to the finishing mill, all of said operations being carried on so rapidly as to render reheating unnecessary; and in connection with said predetermined reduction program'for blanks of varying charac-' teristics, securing the desired dimensional characteristics of the finished pieces by varying the initial temperature to which the blanks are heated.

3. In apparatus for rolling metal to finished sheet gauge directly from heated sheet bars or like sheet blanks not lighter than rough plate and without reheating, which comprises a furnace having temperature control. means, a rough-' ing mill, means for delivering heated blanks from said furnace to said roughing mill, automatic mechanical means for causing said blanks to follow a predetermined series of repeated passes through said mill, means for automatically establishlng with respect to said predetermined.

pass program a predetermined screw-down program, a finishing mill, and mechanical means for delivering the reduced pieces to said finishing mill at the completion of said pass and reduc-' nace, a roughing mill, means for delivering heated blanks from said furnace to said roughing mill, automatic mechanical means for causing said blanks to follow a predetermined series of repeated passes through said mill, means for automatically establishing with respect to said predetermined pass program a predetermined screwdown program, a finishing mill, mechanical means for delivering the reduced pieces to the said finishing mill .at the completion of said pass and reduction program, and means for rapidly varying the temperature to which said blanks are heated by said furnace to produce desired di- 

